More historic than 18% of U.S. towns · #449 of 468 in New Jersey. What drives it
Most of South Plainfield was built recently: 5% of its homes predate 1940 and the median home dates from 1964. Below: 1 old photo or paper, maps from 1888 on, and the census since 1930.
The South Plainfield post office opened in 1887, the earliest record of the town by name. Another post office, New Brooklyn (1877), opened inside today’s town and later closed.
First census: 5,047 in 19302020 census: 24,338139 years
How historic is South Plainfield?
C−
More historic than 18% of U.S. towns, on its age, its old homes and the National Register.
Founding year: the first South Plainfield post office (Blevins & Helbock, CC0).
History grade
What drives South Plainfield’s History grade
On its age, its old homes and the National Register, South Plainfield is more historic than 18% of U.S. towns, #449 of 468 in New Jersey. Its age holds the grade up; its National Register listings pull it down.
C−
HistoryA character grade: shown, never part of South Plainfield’s overall grade.
New Jersey towns list more on the Register than most of the country (a typical New Jersey town has 3.7 per 10,000 residents, the U.S. 2.4), so South Plainfield’s 0.0 sits below most of its state (12% of New Jersey towns have fewer) while its 0 listings outnumber those of 23% of U.S. towns.
How sure. Graded on any two of the three inputs instead, the letter would range from D to C−. The pre-1940 share (±1.3 points) is firm at this size. The founding year is the first post office, not a stated founding date.
Founding year: the first post office (other dates in Quick answers). Homes: Census ACS 2020–24. National Register: National Park Service, May 2026 list; each listing counted once (boundary changes and added documentation belong to their listing), and a historic district counts its contributing buildings. How TownRatings grades history →
What stands out about South Plainfield’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
Every edition of the U.S. Geological Survey’s map of South Plainfield. Tap a year, or press play to watch the town change.
1888Plainfield sheet · 1:62,500
U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of South Plainfield.
The story so far
South Plainfield, in brief
Wikipedia doesn’t have a history of South Plainfield yet. The photos, dates and memories neighbors add here are how it gets written.
South Plainfield is a borough in northern Middlesex County, in the U.S. state of New Jersey. The borough is situated on the border with Union County in the Raritan Valley region, within the New York metropolitan area. As of the 2020 United States census, the borough's population was 24,338, its highest decennial count ever and an increase of 953 (+4.1%) from the 23,385 recorded at the 2010 census, which in turn reflected an increase of 1,575 (+7.2%) from the 21,810 counted in the 2000 census. South Plainfield was incorporated by an act of the New Jersey Legislature on March 12, 1926, from portions of Piscataway, based on the results of a referendum passed on April 6, 1926. The borough's nam…
Its first post office opened in 1887. Between the 2010 and 2020 censuses its population grew from 23,385 to 24,338 (+4%).
Intro from Wikipedia. Population: U.S. Census Bureau.
From the old history books
What they wrote about South Plainfield in 1921
Passages that mention South Plainfield, cut from the printed page as they were published.
History of Middlesex County, New Jersey, 1664-19201921 · page 421Read the page →
Read the text
South Plainfield, a hamlet formerly known as New Brooklyn, is on the Lehigh Valley railroad, and about two miles from Plainfield. It has a school house, postoffice, store, and about 25 or 30 dwellings.
Text read by machine from the scan; it may contain errors.
History of Middlesex County, New Jersey, 1664-19201921 · page 417Read the page →
Read the text
mentioned in 1683, when he had allotted to him 154 acres on the Raritan river. Mather Giles was among the first settlers, and owned farms near Ambrose brook in 1699. Benjamin Clarke and Daniel McDaniel are spoken of in 1683 as owning lands at Samptown, near South Plainfield, and operated a sawmill. Hezekiah Bonham was located near the Green brook. William Clawson was a freeholder in 1690. The family came from Staten Island, and Capt. John was in the Jersey brigade at Albany, New York, in May, 1776. The Boice family were of French extraction,
Text read by machine from the scan; it may contain errors.
Scans and text from the Internet Archive. Books published in 1930 or earlier, which are in the public domain.
Timeline
South Plainfield, 1877 to 1992
Woven from the archive, old maps, post office records, the National Register and the people born here.
The South Plainfield post office opened in 1887, the earliest record of the town by name (U.S. post office records).
How does South Plainfield rank for history?
South Plainfield is more historic than 18% of U.S. towns, #449 of 468 in New Jersey. The History grade combines the town’s founding era, the share of homes built before 1940 and its National Register listings. It’s a character grade, so it isn’t part of the overall grade. How it works.
How old are the homes in South Plainfield?
5% of South Plainfield’s homes were built before 1940 (Census estimate, ±1.3 points), against a typical 15% for a New Jersey town; the median home was built in 1964.
Founding dates: Wikidata, Wikipedia, the U.S. post office records of Blevins & Helbock (CC0) and the Census. Homes by year built: Census ACS 2020–24. National Register of Historic Places: National Park Service (list of May 22, 2026). Old photos, postcards and papers: Wikimedia Commons, the Library of Congress and other public archives, credited on each item’s page. Maps: U.S. Geological Survey historical topographic maps (via Esri) and Sanborn fire-insurance maps (Library of Congress). History text and census tables: Wikipedia (CC BY-SA 4.0). Places that used to be: USGS Geographic Names Information System (2021).
From Wikimedia Commons (3), Wikidata (1), Wikidata and Wikipedia for famous people, U.S. Geological Survey historical maps, U.S. Census counts (via Wikipedia), the US Post Offices dataset (Blevins & Helbock), the USGS Geographic Names Information System and old county and town histories (Internet Archive). Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
Date?
2025
2022